1. Field of the Invention
The present invention relates to an oil management system for an internal combustion engine that comprises a crankcase. The present invention also relates to a method for oil management of such an engine.
2. Description of the Related Art
A large fleet of for example trucks, busses or generator sets generally comprises many different types of internal combustion engines that comprise a crankcase. This large variety of types of engines is not in the least owing to ongoing developments with respect to achieving cleaner internal combustion engines. As each type of such engines requires a specific type of oil, based on their technical standard and temperature circumstances, it has become increasingly difficult to manage oil levels of a large fleet of engines.
Furthermore, checking of an oil level in the crankcase of an engine can be quite difficult because engines for example are being operated continuously or are located at remote places or are being rented and are therefore not easily accessible for maintenance by the owner and/or maintenance personnel. In addition, as it is very difficult to predict the right moment for checking the oil level in the crankcase, typically many unnecessary checks are being carried out. Especially in the case of big fleets this gives rise to significant and in fact unnecessary costs.
A main problem with respect to oil management of an internal combustion engine comprising a crankcase is how to replenish the oil in the crankcase such that the oil level in the crankcase does not drop below a predetermined minimum level and does not exceed a predetermined maximum level. A related problem is how to reliably determine the actual oil level in the crankcase. A first source of inaccuracy with respect to determining the actual oil level in the crankcase might be waiting not long enough after the engine has been shut down before checking the oil level. In this case, not all of the oil has had a chance to flow back into the crankcase yet. Important aspects for determining a sufficiently long waiting time are type of oil used, in particular its viscosity, and temperature conditions under which the engine is operated as this has an impact on the viscosity of the oil. A second source of inaccuracy with respect to determining the actual oil level in the crankcase might be the engine not being in a level position at the time the oil level is being checked.
It is well known that an engine will get damaged if the oil level in the crankcase drops below a predetermined minimum level and a sufficient amount of oil is not replenished in due time. However, if the actual oil level in the crankcase cannot be determined reliably, it practically is a mere guess how much oil has to be replenished. In the case that an amount of oil is replenished such that a predetermined maximum oil level is exceeded the engine can also get damaged eventually as for example oil seals can start leaking due to too high pressure. In addition, excess oil in the crankcase will be burned and possibly contaminates a catalytic convertor of an exhaust system. It will be clear that such a waste of expensive oil and damage to the engine and/or to the exhaust system at least needs to be reduced.
Hence, it is important to be able to replenish the right amount of oil, i.e. an amount of oil such that the oil level in the crankcase will be between predetermined minimum and maximum levels. In addition, it is important to be able to replenish the right type of oil for each specific type of engine.